CYPERACE^E. (SEDGE FAMILY.) 569 



tipped with a minute depressed and apiculate tubercle , the delicate bristles four 

 or five times shorter or obsolete. — Bogs in pine barrens of New Jersey ( W. M. 

 Canby, C. F. Parker), and in N. Carolina. 



H _ +- .!_ Bristles long, denticulate downwardly, or both ways in No. 12. 



+* Spikes white or whitish, becoming tawny icith age, perfecting only a single flower : 



stamens usually 2 : bristles 9-12, or even 20 



8. R. alba, Vahl. Culm slender (1°- 2° high), triangular above ; leaves 

 narrowly linear or almost bristle-form ; spikes lanceolate, densely crowded in a 

 head-like terminal corymb and usually one or two lateral ones ; achenium ob- 

 long-obovate with a narrowed base, scarcely longer than the flattened-awl- 

 shaped tubercle, shorter than the bristles. — Bogs, especially eastward. (Eu.) 

 ++ ++ Spikes chestnut-colored or darker in No. 11 and 12, few -several-flowered: 



stamens 3 : bristles usually 6. 



9. R. capillacea, Torr. Leaves bristle-form; spikes 3-6 in a terminal 

 cluster, and commonly 1 or 2 on a remote axillary peduncle, oblong-lanceolate 

 (pale chestnut-color, 3" long); achenium oblong-ovoid, stipitate, very obscurely 

 wrinkled, about half the length of the (6, rarely 12) stout bristles, and twice the 

 length of the lanceolate-beaked tubercle. — Bogs and rocky river-banks, Penn. 

 to N. Vermont, New York, and Michigan. — Culm 6' -9' high, slender. 



10. R. Kniesk&rnii, Carey. Leaves narrowly linear, short; spikes numer- 

 ous, crowded in 4-6 distant clusters, oblong-ovate (scarcely 1" long); achenium 

 obovate, narrowed at the base, equalling the bristles, twice the length of the trian- 

 gular flattened tubercle. — Pine barrens of New Jersey, on bog iron ore exclu- 

 sively (Knieskern), and southward : rare. — Culms 6'- 18' high, slender. 



11. R. glomerata, Vahl. Leaves linear, flat; spikes numerous in distant 

 clusters or heads (which are often in pairs from the same sheath), ovoid-oblong; 

 achenium obovate, margined, narrowed at the base, as long as the lance-awl- 

 shaped flattened tubercle, which equals the (always) downwardly barbed bristles. 

 — Low grounds : common, especially eastward. — Culm 1° - 3° high. — A state 

 with small panicled clusters is R. paniculata, Gray. 



12. R. cephalailtha, Torr. Leaves narrowly linear, flat, keeled; spikes 

 very numerous, crowded in 2 or 3 or more dense globular heads which are distant 

 (and often in pairs), oblong-lanceolate, dark brown ; achenium orbicular-obovate, 

 margined, narrowed at the base, about as long as the awl-shaped beak, half the 

 length of the stout bristles, which are barbed downwards and sometimes also up- 

 wards. — Sandy swamps, Long Island to New Jersey, and southward. — Culm 

 stout, 2° - 3° high : the fruit larger than in the last, of which it may be only 

 a marked variety. 



§ 3. CERATOSCHCENUS, Nees. Spikes spindle-shaped or lanceolate, acumi- 

 nate, in fruit flatiish, large, cymose-panicled, producing only one perfect and 1 to 4 

 staminate flowers ; their scales few, the lower mostly empty : stamens 3 : bristles of 

 the perianth rigid, either short or slender, minutely scabrous upward: style simple 

 or barely 2-toothed at the apex, fl/ifbrm and gradually thickened downwards, in 

 fruit almost all of it persistent as a very long, exserted, slender-awl-shaped, 

 upwardly roughened beak, several times longer than the smooth and flat obovate 

 achenium : coarse perennials : spikes in flower 4", in fruit including the pro' 

 L&M— 44 



